[OpenAFS] Severe Performance Issue with SCSI!

[Rubino Geiß]

Hi all,

what do you know about SCSI and OpenAFS performance?

Our main server is a SCSI system with 6 disk (10k RPM, 32GB, 160 LDV) on
2  Adaptec controllers. This setup is 2-4 times slower than a similar
system using IDE-drives (5,4kRPM, 40GB). 

I have already tested several other SCSI disk and host adapters along
with different computers and several version of Redhat Linux (7.1, 7.2,
7.3). All I get out of these experiments is the fact, that OpenAFS
crawls if you use SCSI. Even RAID 1 and 2 and 5 (all tested) doesn't
help. 

Some AlphaServer, Tru64 UNIX 5.1 (IBM AFS) seems to perform well even
with  SCSI; actually this nearly 10 year old machine 10MBit interface is
even as fast as our fastest IDE-server running OpenAFS.

Our LAN is a switched 100 MBit Ethernet. 

The test case is derived from our main application: compiler
construction. That is touching and reading many small files. Building
many rather small temporary files and directories.

Your help is very appreciated.

Thank you, Rubino


--
Rubino Geiss, Universitaet Karlsruhe, IPD Goos
Postfach 6980, D-76128 Karlsruhe, GERMANY
Adenauerring 20a, 50.41 (AVG), Zi. 235
rubino@ipd.info.uni-karlsruhe.de
Tel: (+49) 721 / 608-8352
Fax: (+49) 721 / 30047